1. Field of the Invention
The present invention relates to display screens, and particularly to an automatically illumination control device of an elevator display screen for controlling the illumination of the light emitting elements of the display screen.
2. Description of Related Art
Elevators are necessary devices for tall buildings. In general display screens are installed beside or above the elevator doors for displaying the traveling condition of the elevator, as shown in the FIG. 1. The current display screen is mainly formed by LEDs which have constant illuminations independent of the intensity of environment light. However, this prior art has the following disadvantages:
1. Since the intensity is fixed, the illumination is weak in daytime so that the user can not see the display content clearly.
2. At night, the illumination of the display screen is too strong to feel comfortably.
3. When deep in the night, the display screen has a fixed illumination, not only power is wasted, but also the lifetime is reduced. Moreover, the structure of the display screen will deteriorate.
To improve above detect, some elevator display screens are added with sleep devices. When for a time period, an elevator is not been used, the illumination of the display screen will become dark so as to save power and prolong the lifetime. However, this improvement can not be resolve the problem induced from the change of the environment light.
Accordingly, the primary object of the present invention is to provide an automatically illumination control device of an elevator display screen, wherein the light sensor detects the illumination of the environment light and the illumination of the display screen is controlled automatically by using a control circuit so as to present a soft light which is warm to the viewer. Moreover, the automatically illumination control device has the advantages of power saving and long lifetime.
To achieve the object, the present invention provides an automatically illumination control device of an elevator display screen having an elevator display screen; the display screen being installed with a driving circuit; the display screen having a microprocessor, a control circuit and at least one light sensor; wherein the elevator display screen is installed with an array of light emitting elements. The light sensor is installed to the display screen for detecting environment light out of an elevator and then outputting the signals to the control circuit. The control circuit comparing signals outputted from the light sensor and transferring the signals to the microprocessor. The microprocessor performing operation; and the display screen serves to change illumination of light outputted to the display screen.
The advantages of the present invention will be described in the followings.
1. When the light sensor feels that the environment light is intense, the illumination of the display screen will increase so as to be identified easily.
2. When the environment light is weak, the illumination of the display screen will decrease so as to be identified easily.
3. The illumination of the display screen is adjusted intelligently so that the display screen has a proper illumination and thus the lifetime of the display screen is prolonged. The material of the display screen can not be deteriorated.
4. The display screens of different stories has different illuminations.